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EWG's Tap Water Database — 2021 UPDATE

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Perfluorooctane sulfonate (PFOS)

California American Water Company - Monterey

Perfluorooctane sulfonate (PFOS) is a member of a group of perfluorinated chemicals used in many consumer products. PFOS and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.

MORE ABOUT THIS CONTAMINANT

 

43

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013ND70ND
2014ND130ND
2015ND30ND
2016N/A00N/A
2017N/A00N/A
2018N/A00N/A
20190.615 ppt202ND - 6.20 ppt

ppt = parts per trillion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppt

The EWG Health Guideline of 1 ppt for PFOS was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline applies to the entire class of PFAS detected in water.

EPA Maximum Contaminant
Level (MCL) 4 ppt

ppt = parts per trillion

All test results

Date Lab ID Result
2013-09-0923390901ND
2013-09-1123389701ND
2013-09-1123386401ND
2013-09-1123391101ND
2013-10-0723388801ND
2013-10-3023389101ND
2013-12-1624208001ND
2014-03-102993620ND
2014-03-102993625ND
2014-03-112993614ND
2014-03-112993668ND
2014-03-112993666ND
2014-04-0924999801ND
2014-05-0524994801ND
2014-05-0525000201ND
2014-05-0525000401ND
2014-06-1825824401ND
2014-12-1626925201ND
2014-12-1628049401ND
2014-12-1626924901ND
2015-05-0429260201ND
2015-06-1827426301ND
2015-07-2329998701ND
2019-05-091225-051-1445ND
2019-07-291225-044-1445ND
2019-07-291225-045-1452ND
2019-08-221225-051-1725ND
2019-10-071225-051-1420ND
2019-12-021225-026-1538ND
2019-12-021225-002-1626ND
2019-12-021225-074-1619ND
2019-12-021225-073-1524ND
2019-12-021225-072-1448ND
2019-12-021225-070-1304ND
2019-12-021225-052-1600ND
2019-12-031225-092-1452ND
2019-12-051225-046-1630ND
2019-12-091225-024-1730ND
2019-12-091225-029-17106.20 ppt
2019-12-101225-006-1457ND
2019-12-111225-048-1644ND
2019-12-111225-050-1740ND
2019-12-191225-029-14076.10 ppt